I manage a decent amount of computers on a domain at my workplace, so I need to disable the "great" new Delivery Optimization feature through a Group Policy or Registry setting. It just isn't feasible to go to each PC (especially remote ones hundreds of miles away) and disable it. Also, users cannot be trusted to disable this on their own and I can't stop them from re-enabling it for some unknown reason.
On top of that, many employees are in a data capped trap at home, so they'll be asking me why they are suddenly charged an extra $50+ overage fee a month pretty quickly.
While I'm sure it is secure and all (everything in an operating system always is!), in a workplace environment it is a risk to receive anything like a security related update from other users (local network or internet).